<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            width: 300px;
            height: 300px;
            background-color: aqua;
        }
    </style>
</head>
<body>
    <div class="box"></div>
    <script>
        const oBox = document.querySelector(".box");

        function center(e){
            console.log('center');
            console.log(e);
            console.log(this);
        }

        function throttle (fn,time){
            console.log(1);
            let lastTime = 0;
            return function (e){
                let nowTime = Date.now()

                //书写一个看门狗
                if(nowTime-lastTime < time){
                    return
                }

                lastTime = nowTime
                // center(e)
                fn.call(this,e)
            }
        }

        oBox.onmousemove = throttle(center,300)
    </script>
</body>
</html>